Patent GB-422443-A (GB)
Title: Improvements in an automatic clutch
IPC: F16D43/12
Filed: 1934-03-07
Abstract: 422,443. Friction clutches. DEHN, F. B., 103, Kingsway, London.-(Borg-Wamer Corporation; 310, South Michigan Avenue, Chicago, U.S.A.) March 7, 1934, No. 7296. [Class 80 (ii)] A single-intermediate-plate clutch is normally engaged by springs 26, Fig. 1, and is adapted to be disengaged through radial levers 31 by movement to the left of a pedal-operated collar 28, while centrifugally-acting spring-controlled means are provided, which, below a predetermined speed, cause the clutch to disengage and, above that speed, have no effect on the clutch. Means are also provided for rendering the centrifugal control inoperative. Weights 45 pivoted at 47 to the clutch cover 12 are connected by links 50 to levers 52 pivoted at 67 to the cover 12, retracting springs 56 abutting against lugs 55 projecting from the cover 12. Rollers 59 carried by the levers 52 coact with the flange 38 of a slidable sleeve 39, to which latter are pivoted pawls 40 having hooks 42 which are normally maintained by springs 60 in engagement with pins 43 on the levers 31. Below a predetermined speed, the effect of the springs 56 overbalances the effect of the springs 26, and the clutch is disengaged. Above that speed, the weights 45 move out and the sleeve 39 is no longer influenced by the springs 56. Projections 61 on the pawls 40 coact with cams 62 on a spring-pressed sleeve 63 which is adapted to be moved to the left by a flanged sleeve 64 moved by the collar 28. Thus, with the clutch engaged, if the collar 28 is moved to the left to disengage the clutch, the hooks 42 are disengaged from the pins 43. During the return movement of the collar the hooks will re-engage the pins if the sleeve 63 is permitted also to return. Such return movement of the sleeve 63 may be prevented, so as to render the centrifugal control inoperative, by causing a plunger 69, which is carried by the sleeve 64 and engages a slot 71 in a supporting member 29, to engage a hole 72 in the member 29. The driven clutch plate 19 is resiliently connected to its splined hub 18 by means of projections 21 on the hub which are engaged by complementarily-shaped rubber discs 22 held between the plate 19 and a disc 23 by rivets 24. In the modification shown in Fig. 6, the pawls 40 are weighted at 89 and controlled by springs 90. Disengagement of the hooked connection between the pawls and the levers 31 is effected by moving the collar 28 to the left beyond the position corresponding to disengagement, when the speed is low enough to allow the springs 90 to overcome the centrifugal force of the pawls. Re-engagement of the hooked connection is effected by a similar movement of the collar 28 after the speed has been increased. A releasable stop is provided which normally prevents movement of the clutch pedal beyond the disengaged position. In the modification shown in Fig. 5, the pawls 40 are omitted and, instead of the rollers 59, the levers 52 have spring-pressed pawls 80 hooked to engage a ridge 78 on a sleeve 76 which has a flanged end maintained in engagement with the inner ends of the levers 31 by springs 79. Thus, below the predetermined speed, if the collar 28 is moved to the left beyond the disengagement position the pawls 80 are tilted outwards by the ridge 78 and are so held by detents 83 which engage shoulders 84 on the pawls, thus rendering the centrifugal control inoperative. When the predetermined speed is, however, exceeded, and the weights 45 swing out, the shoulders 84 are released from the detents.